When components are mounted on a substrate transported along a transport path, the substrate is raised from behind by means of support pins positioned along the transport path, and front sides of both ends of the substrate are fixedly pressed against transport rails making up a transport path. The substrate is thereby supported at a predetermined height, and components are mounted on the front side of the substrate. After the components have been mounted, the support pins are once caused to recede in a downward direction from a back side of the substrate. The substrate released from a fixed state is transported to the next process, and a new substrate is carried into the transport path. The thus-receded support pins are again raised, to thus support the new substrate (see Patent Document 1).    Patent Document 1: JP-A-1-146400